A345054 Odd numbers k such that A173557(k) divides nonzero A051709(k).

27, 243, 1377, 2187, 3125, 19683, 28125, 55233, 68445, 177147, 195625, 203125, 239805, 253125, 453125, 823543, 907137, 1323297, 1378125, 1464561, 1594323, 1953125, 2278125, 3341637, 3572829, 5255361, 5877117, 9034497, 9819837, 11701053, 14348907, 17453125, 19460393, 20503125, 22209633, 26010621, 30074733, 44910045

Offset

1,1

Comments

Question: Are there any common terms with A345051?

Links

Table of n, a(n) for n=1..38.

Index entries for sequences where odd perfect numbers must occur, if they exist at all

Prog

(PARI)
A051709(n) = ((sigma(n) + eulerphi(n)) - (2*n));
A173557(n) = factorback(apply(p -> p-1, factor(n)[, 1]));
isA345054(n) = if(!(n%2), 0, my(u=A051709(n)); ((u>0)&&(0==(u%A173557(n)))));

Crossrefs

Odd terms in A344994.

Cf. A051709, A173557, A345051.

Sequence in context: A183806 A207104 A075548 * A074117 A030509 A042414

Adjacent sequences: A345051 A345052 A345053 * A345055 A345056 A345057

Keyword

nonn

Author

Antti Karttunen, Jun 06 2021

Status

approved